Existing intravascular nozzles or catheters, being the prior art, comprise a plastic material tube with an end designed to be housed within the punctured blood vessel and its other end connecting with a serum equipment via a "Luer-lock" system. Running along the inside of the nozzle is the needle allowing puncture and fitted at its far end with a receptacle which on being filled indicates that the needle is correctly positioned within the blood vessel.
Once the blood vessel has been punctured the needle is removed and the plastic nozzle is inserted until it reaches its definitive position. The serum equipment is finally connected at the end of the nozzle via the so-called "Luer-lock" system.
This latter operation, even if carried out skillfully and at great speed, usually entails the outlet of drops or indeed greater quantities of blood. This means that the operator will come into contact with the patient's blood and hence there will clearly be a risk of contamination and contagion if the patient carries any infectious diseases (hepatitis, AIDS, and so forth). In any event, even if there are no chances of contagion, the need to clean the area stained by the refluxing blood will always be a problem and the sterility of the material used will moreover be at stake.